The University of Southampton
University of Southampton Institutional Repository

Mid-infrared Integrated photonic devices for biosensing

Mid-infrared Integrated photonic devices for biosensing
Mid-infrared Integrated photonic devices for biosensing
This thesis describes the realisation of devices and techniques based on evanescent field sensing using planar optical waveguides for mid-infrared (MIR) absorption spectroscopy, to provide bio-chemical sensing capabilities for medical diagnostics. The fundamental vibrations of bio-chemical molecules occur in the MIR region, where their absorption is orders of magnitude stronger than their overtone bands in the near-infrared making it suitable for highly sensitive and specific absorption spectroscopy. Realisation of waveguides is an essential step towards mass-producible and low-cost integrated lab-on-chip devices. Two chalcogenide compositions were used to make waveguides, germanium telluride (GeTe4) as waveguide core and zinc selenide (ZnSe) as waveguide lower cladding. Two approaches were followed for waveguide fabrication: GeTe4 waveguides on bulk ZnSe and GeTe4 waveguides on thin films ZnSe deposited on Si. High contrast (Δn ~ 0.9) GeTe4 channel waveguides on ZnSe were fabricated using photolithography and lift-off. Waveguiding was demonstrated for the wavelength range between 2.5 and 9.5 μm for GeTe4 channel waveguides on bulk ZnSe substrates. GeTe4 waveguides fabricated on Si with ZnSe isolation layers were characterised for waveguiding and propagation losses in the wavelength range between 2.5 and 3.7 μm. ZnSe rib waveguides were also fabricated on oxidised Si by photolithography and dry etching and were characterised for propagation losses in the wavelength region of 2.5-3.7 μm. Absorption spectroscopy of liquid mixtures absorbing in the MIR was performed on the surface of the waveguide and the results were compared with a theoretical model.
University of Southampton
Mittal, Vinita
fd5ee9dd-7770-416f-8f47-50ca158b39b0
Mittal, Vinita
fd5ee9dd-7770-416f-8f47-50ca158b39b0
Wilkinson, James
73483cf3-d9f2-4688-9b09-1c84257884ca

Mittal, Vinita (2017) Mid-infrared Integrated photonic devices for biosensing. University of Southampton, Doctoral Thesis, 190pp.

Record type: Thesis (Doctoral)

Abstract

This thesis describes the realisation of devices and techniques based on evanescent field sensing using planar optical waveguides for mid-infrared (MIR) absorption spectroscopy, to provide bio-chemical sensing capabilities for medical diagnostics. The fundamental vibrations of bio-chemical molecules occur in the MIR region, where their absorption is orders of magnitude stronger than their overtone bands in the near-infrared making it suitable for highly sensitive and specific absorption spectroscopy. Realisation of waveguides is an essential step towards mass-producible and low-cost integrated lab-on-chip devices. Two chalcogenide compositions were used to make waveguides, germanium telluride (GeTe4) as waveguide core and zinc selenide (ZnSe) as waveguide lower cladding. Two approaches were followed for waveguide fabrication: GeTe4 waveguides on bulk ZnSe and GeTe4 waveguides on thin films ZnSe deposited on Si. High contrast (Δn ~ 0.9) GeTe4 channel waveguides on ZnSe were fabricated using photolithography and lift-off. Waveguiding was demonstrated for the wavelength range between 2.5 and 9.5 μm for GeTe4 channel waveguides on bulk ZnSe substrates. GeTe4 waveguides fabricated on Si with ZnSe isolation layers were characterised for waveguiding and propagation losses in the wavelength range between 2.5 and 3.7 μm. ZnSe rib waveguides were also fabricated on oxidised Si by photolithography and dry etching and were characterised for propagation losses in the wavelength region of 2.5-3.7 μm. Absorption spectroscopy of liquid mixtures absorbing in the MIR was performed on the surface of the waveguide and the results were compared with a theoretical model.

Text
Vinita Mittal Thesis final - Version of Record
Available under License University of Southampton Thesis Licence.
Download (9MB)

More information

Published date: April 2017

Identifiers

Local EPrints ID: 416430
URI: http://eprints.soton.ac.uk/id/eprint/416430
PURE UUID: 42d3c659-a90b-4275-96fc-a5f87b3a7888
ORCID for Vinita Mittal: ORCID iD orcid.org/0000-0003-4836-5327
ORCID for James Wilkinson: ORCID iD orcid.org/0000-0003-4712-1697

Catalogue record

Date deposited: 15 Dec 2017 17:31
Last modified: 30 Jan 2020 01:45

Export record

Contributors

Author: Vinita Mittal ORCID iD
Thesis advisor: James Wilkinson ORCID iD

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×